Magnetic resonance imaging (MRI) is an imaging technique of magnetically exciting, by using RF signals at the Larmor frequency, the nuclear spin of a test object located in a static magnetic field, and recomposing an image from MR signals generated by the excitation. In the observation of a living body, signals of hydrogen nucleuses are mainly observed.
MRI technology has already had many applications in the medical diagnosis field. In addition, in the neuroimaging study using the MRI, there are some reports pointing out the relationship of the character tendency to the brain morphology and function in the structural MRI study (Non Patent Literature 1, Non Patent Literature 2, Non Patent Literature 3).
For example, Non Patent Literature 1 has reported a study about the correlation of the volumes of the gray matter and white matter in the frontal lobe and temporal lobe limbic system to the feature of the temperament and character. Further, Non Patent Literature 2 has reported that the volumes of the white matter and cortex in the cerebellum correlate with the feature of the temperament.
The temperament, for example according to the Cloninger theory, is considered at four dimensions: (1) Novelty seeking (NS, the inspiration of behavior), (2) Harm avoidance (HA, the suppression of behavior), (3) Reward Dependence (RD, the maintenance of behavior), and (4) Persistence (P, the fixation of behavior). The character is considered at three dimensions: (1) Self directedness (SD, autonomous individual), (2) Cooperativeness (C, the integral part of the human society), and (3) Self-transcendence (ST, the integral part of the universe).
Also, another technology different from the MRI technology has been proposed as a device for measuring the brain function. This technology estimate or predict the internal state of individuals such as the attention and the memory, using brain function measurement signals obtained from optical topography, and prevent and avoid human errors by detecting a state prone to human errors and by giving a warning (Patent Literature 1).
Thus, such a ergonomic application using the objective brain information for determining the tendency of the character of a person or for judging the current awareness state have been studied.
Furthermore, in the MRI technology described above, diffusion tensor imaging (DTI), developed in recent years, enables visualizations such as a stereoscopic visualization of the pyramidal tract, the corpus callosum and the like, and a visualization of the positional relationship between these and a nidus such as a tumor, based on the quantitative evaluation of the diffusion anisotropy closely associated with the density of the white matter, the degree of the degeneration and the like. The usefulness of this imaging method has already been demonstrated in clinical practice because it enables diagnosis which could not be done with other imaging method (Non Patent Literature 4).
The DTI images that the water-molecule diffusion direction is mainly restricted by the axis cylinder and myelin sheath of the nervous system, by using the MRI technology.
The DTI quantifies the diffusion anisotropy, for example, with an index such as a FA (Fractional Anisotropy) value.
In such a DTI, there is a proposal about the setting method for an imaging target region in the DTI without depending on subjectivity or skill of a tester (Patent Literature 2).
In learning process, it is important to instruct a student according to the personality thereof. There has been a proposed system for discriminating the personality of the student by a written test, and for creating the information about an instruction guideline and a proceeding way of the learning (for example, Patent Literature 3). In the Patent Literature 3, the personality of a person is converted, using the answers to 80 questions, to five numerical factors, which are condensable property, receptive property, discriminable property, diffusible property, and preservative property and stress.